
SOI* 




Class 

Book 

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COPYRIGHT DEPOSIR 



A HIGH SCHOOL COURSE 

IN WOOD PATTERN 

MAKING 

By 

Joseph Henry Wilson 

Instructor in Pattern Making, Central High School 
Washington, D. C. 

Formerly instructor at McKinley Manual Training School 



Washington, D. C. 
1916 






Copyright, 1916 

By 

Joseph Henry Wilson 



DEC -5 1316 



■0: 



1 6 -14115 

CI.A446713 



PREFACE 

This book is the outgrowth of seven years of 
teaching experience in both Trade and High 
Schools. The author submits the book on the 
ground that we can all benefit by the experience 
of others. Works on Pattern Making are not as 
numerous as the importance of the subject 
warrants. 

The various articles in this book follow each 
other in what seems to the author to be the 
natural sequence. To begin the subject the 
teacher lectures on The Metal Trades (Chapters 
I and II), and the manufacture of iron products, 
so that the pupil can learn exactly what part pat- 
tern making plays in the commercial world. Then 
the wood working exercise in Chapter III should 
be started. Before beginning it, however the 
pupils, as a class, should be made to remove the 
plane bit and sharpen it and learn to replace it 
correctly. Pupils dislike to take a plane apart 
until the teacher proves to them that it is a simple 
operation. 

While the pupil is working on the exercise, 
certain periods should be devoted to lectures and 
recitations on Moulding and Pattern Making, 
(Chapters IV and V,' so that these chapters are 
covered by the time the exercise is finished. 
Then the student will understand and can begin 
making the simple patterns in Chapter VI. If 



lathes are scarce in the shop some pupils may be 
put at turning immediately after the first pattern. 
These pupils can then go back to the bench while 
others are turning. From parted patterns, to the 
end, the time spent on the bench preparing the 
pattern for the lathe, making the core box and 
finishing, exceeds the time spent at the lathe 
and a student need never be idle while waiting 
a chance to get on a lathe. Each student must 
have a bench. 

Each individual kit of tools should be as small 
as possible. Large kits are difficult to keep track 
of. Each boy needs only : bevel, square, back 
saw, gage, scribe, dividers, rule, dust brush, jack 
plane, block plane, y 2 " chisel, i" chisel, fy" inside 
gouge, and Y" outside gouge. Sharpening out- 
fits must be as convenient as possible. If pos- 
sible supply each bench with an oilstone. 

Other tools are necessary but as they are not 
frequently used, a few of each may be kept in a 
convenient wall cabinet. There should be at 
least one-third as many lathes as there are pupils 
in the shop at one time and as many face plates 
as there are pupils taking the course. A band 
saw is indispensable. 

Experience gained while a student at the Wil- 
liamson School of Mechanical Trades enabled the 
author to arrange the course and his ten years 
experience as a pattern maker in large commer- 
mercial shops enabled him to present actual 
shop methods. 



CONTENTS 

CHAPTER I— The Metal Trades i 

The Machinery Manufacturing Plant. 

CHAPTER II— Benefits of Shop Course 6 

CHAPTER III— Woodworking 9 

Tools. Exercise in Working to Scribe and 
Gage Lines with Saw and Chisel. Instruc- 
tion card. 

CHAPTER IV— Moulding 20 

Loam, Dry Sand and Green Sand Moulds, Tools 
Terms, Cores, Shrinkage of Metals, Shrinkage 
Rule, Draft, Parted Patterns; making a Mould. 

CHAPTER V— Pattern Making 39 

Definition, Lumber, Drawings, Allowances in 
Pattern Making. 

CHAPTER VI— Bench Work 48 

Pattern No. 1, Introducing finish, shrinkage 
and draft, Shellac. No. 2, Introducing Green 
Sand Cores. No. 3, What to do with small 
holes. 

CHAPTER VII— Wood Turning 57 

Cylinder, Beads, Coves. Its Relation to 
Pattern Making. Sharpening Lathe Tools. 

CHAPTER VIII— Turned Patterns 65 

Bushing. To Shellac on the Lathe. A Parted 
Pattern. Hollow Cylinder. The Core Box. 

CHAPTER IX— Gouge and Templet Work 75 

The Templet, Drip Cup, Built Up Work, Rail 
Stop, Fillets, Tail Prints. 

CHAPTER X— Face Plate Work 82 

The Chuck or Face Plate, Cylinder Cover, 
Spear Point Tool, Rechucking, Segments, 
Piston Ring, Lead Ladle, Locomotive Bell. 

CHAPTER XI— Wheels 96 

Hand Wheel. Gear Blank, Arms, Gear Wheel. 
CHAPTER XII— Staves and Strips 103 

Flange Pipe, Stripped up Core Box, Loose 
Pieces. Cylinder Cover. 



CHAPTER I. 

THE METAL TRADES 

As you walk along the streets of a city and 
observe the ornamental lamp posts, the U. S. mail 
boxes, or the fire plugs, or, as you hear the bell or 
whistle of a locomotive or the chug-chug of a 
gas or steam engine, has it not at some time ex- 
cited in you a curiosity to know the processes by 
which such things come into being? Did it ever 
occur to you that the motor in your father's 
automobile, the parts of your mother's sewing 
machine, the hardware in your home, the plumb- 
ing fixtures in your bath room, or the pipe fittings 
and steam radiators which help make you com- 
fortable, or even the artistic bronze statues which 
help beautify your parks, might be produced by 
processes which would prove to be a great deal 
more interesting to you than anything into which 
you have yet inquired? It is the purpose of these 
pages to get you interested in this art ; the art 
of manufacturing metal objects, such as those 
mentioned above, and countless others. 

To begin at the beginning, let us follow the 
manufacture of some new machine. 

Your History has taught you that some clever 
men such as Watt, Whitney, and Fulton, first 
perfected certain new commodities, which were 

1 



2 A High School Course 

of great benefit to mankind. You call them in- 
ventors. In those days inventions were produced 
only after long and tedious experiments with 
moving models. Nowadays when an inventor 
conceives a new machine, he sets it down on paper. 
He figures out its moving parts and their required 
strength, etc., often without attempting to make 
a working model. The result is a "drawing." 
With this drawing he tells others what has been 
in his mind. Drawing is the universal language 
of the engineer. 

The inventor may not have an engineering 
education. In that case, he is obliged to employ 
an engineer to design his machine. After the 
designer has proportioned the parts, the draftsman 
draws the details accurately to scale and then a 
tracing and blue prints are made. 

The blue prints are sent to a pattern maker, who 
reads them and fixes in his mind the idea that the 
designer intends to convey. He then proceeds to 
fashion certain forms in wood somewhat re- 
sembling the parts of the new machine. These 
forms are called patterns. 

The patterns are then sent to the foundry where 
a workman called the moulder buries them in a 
special kind of sand and packs the sand hard 
around them. Then by ingenious methods, which 
have been anticipated by the pattern maker, he 
withdraws the pattern from the sand, leaving the 
full impression of the pattern in the sand. This 
impression is called the mould. 



In Wood Pattern Making 3 

While the moulder is preparing the mould, the 
foundryman is firing up his cupola in which he 
melts bars of pig iron and quantities of scrap iron. 
When the iron is brought to a molten state, he 
rams a clay plug out of a tap hole near the bottom 
of the cupola, letting the molten metal flow down 
through a trough into a clay lined ladle in which 
it is carried to be emptied into the mould. 

When the metal has cooled and is dug out of 
the sand, it is found to have the shape that was 
planned for it by the pattern maker and is called 
a casting. 

To free the casting from the particles of sand 
which adhere to it, it is sent to the cleaning de- 
partment, where it is tumbled around in a large 
revolving cylinder called a tumbling barrel or it is 
subjected to other treatment. The cleaned cast- 
ing now goes to the machine shop. 

These castings are somewhat rough ; so in order 
that the parts of the machine we are building can 
run smoothly together, we must finish them off 
smooth on the surfaces which come into contact 
with each other. To that end, the machine shop 
is equipped with drill presses and boring mills for 
boring holes, lathes for turning cylindrical pieces, 
planers and shapers for making flat surfaces so 
that two pieces may be made to slide smoothly 
on one another or fit snugly together, milling- 
machines, and other machines whose variety and 
functions are too numerous to mention. 

After the castings have been finished, they are 



4 A High School Course 

sent to the assembling or erecting shop, where 
they are all carefully fitted together to make the 
complete machine. 

Cast iron is brittle, and when made into slender 
shapes, is in danger of being broken if subjected 
to a shock. It is desirable to make such parts 
from a tougher material; therefore, wrought iron 
is used. Wrought iron cannot be melted in the 
cupola and poured into the mould. It is made red 
hot and hammered into the reuired shape. This 
work is done in the forge shop. 

The student should know the above depart- 
ments in their proper sequence and the function 
of each. 

Departments Constituting a Machinery Manu- 
facturing Plant and Their Functions 

i. Drafting room: where the machine is 
planned and drawings made. 

2. Pattern shop ; where the forms for use in 
making the moulds for the parts are made. 

3. Foundry ; where the moulds and castings 
are made. 

4. Forge shop ; where the wrought iron parts 
are hammered out. 

5. Machine shop ; where the castings are 
finished. 

6. Assembling shop ; where the machine is 
fitted together. 

Compare this with a modern technical high 



In Wood Pattern Making 5 

school and you find that the high school is often 
a complete machinery manufacturing plant. 

In a commercial shop the apprentice to any one 
of the above trades learns only his own trade. 
Think of the tremendous advantage you have over 
him since you will get a knowledge of all. 



CHAPTER II. 

BENEFITS OF SHOP COURSES 

You may wish to finish your education at an 
engineering college. Then you must know the 
trades, for they are the very foundation of en- 
gineering. 

You may wish to be a draftsman. You will 
then be required to make drawings of objects that 
are to be made by the processes involved in these 
trades. Your knowledge of these processes will 
serve you, in that you can design the objects so 
that it will be possible to make them by these 
processes. You will be more valuable to your 
employer than the office trained draftsman. 

You may live in a community where the manu- 
facture of iron products is the chief industry and 
there is a great field for mechanics. It would be 
natural for you, under these circumstances, to 
wish to learn one of the trades and you would 
be apt to think the others of no importance to 
you. As a matter of fact, a knowledge of the 
other trades would make you a broader and more 
efficient mechanic in your own line and you 
would rise above the average. 

In no trade, however, is a knowledge of the 
others as essential as in the trade of pattern 
making. 

The pattern maker must understand mechanical 
drawing as well as the draftsman himself under- 

6 



In Wood Pattern Making J 

stands it ; for he must not only read the drawing, 
but actually lay it out full size, no matter how 
large, before beginning the pattern. Every pat- 
tern shop possesses a stack of large and small 
drawing boards one of which is selected by the 
pattern maker who places it on a pair of horses, 
planes off the old drawing and proceeds to lay 
down a full size drawing of his new job ac- 
curately, scratching the lines on the board with 
a sharp scribe or knife. 

It is obvious that the pattern maker must know 
moulding; since he must anticipate the needs 
of the moulder and so arrange the parts of the 
pattern that the moulder can draw the pattern 
out of the sand without breaking down any part 
of the mould. He must understand enough about 
machine shop practice to be able to act on his 
own account in such matters, as adding metal 
here or there for the machinist to plane or turn 
off in order to get a smooth surface on the cast- 
ing. It often happens that he must decide where 
to put certain lugs or projections on the pattern, 
which do not appear on the drawing, but which 
are used by the machinist in chucking or center- 
ing the work in the machine. 

In addition to this knowledge, the pattern 
maker must be highly skilful with the wood work- 
ing tools in order to produce patterns which are 
smooth and clean cut. The ability to operate 
machine tools or wood working machinery is 
necessary. A surprising variety of work can be 
done on such machines by one who will take the 



8 A High School Course 

trouble to learn how. An illustration of what 
can be done on the circular saw can be found in 
the Oliver Catalog, Students in elementary 
pattern work will, however, have little except 
plain work on these machines. 

Above all, the pattern maker must possess re- 
sourcefulness and be willing to use it continually, 
No mentally lazy person can become an efficient 
pattern maker, Any number of castings can be 
produced by the use of a single pattern ; therefore, 
the pattern maker seldom has two jobs alike, 
Each new job calls for original thinking, planning 
and scheming. This thinking covers the whole 
range of the metal trades. 

While the pattern maker works in wood, he 
has little in common with the carpenter and 
cabinet maker. His thoughts are mostly on metal. 
Therefore pattern making is classed among the 
metal trades. 

From the foregoing it will be seen that in 
order to complete a course in pattern making 
hard work is requited. Your teacher has a right 
to expect it from you. He has a right to suppose 
that you want this kind of work or you would 
not attend a manual training school. If you lean 
toward business or a profession you should have 
attended a commercial or academic school. But 
the author wishes to state that one who has no 
intention of following a mechanical pursuit, will 
find that the knowledge gained in this work will 
give him greater satisfaction, in after life, than 
many other things he has learned at school. 



CHAPTER III 

WOODWORKING. 
Exercise I. (See Drawing, Fig. 8.) 

Most pupils who take a course in pattern 
making have had a course in woodworking or 
cabinet making in the lower schools, therefore, 
it is not necessary to begin at the beginning. 
Many bad habits in the use of tools are formed by 
pupils, however ; so this exercise, while it has 
nothing to do with pattern making, will serve as a 
review for the student and an opportunity for 
the teacher to correct bad habits before the more 
serious business of pattern making is taken up. 
As will be found later, the pattern maker's 
thoughts and reasoning are mostly in metal ; 
therefore the student should be so familiar with 
wood work before he begins on patterns, that the 
wood working will not give him much concern. 
Considering then that the student has handled 
tools before and knows something about them, 
we will call attention only to the common mis- 
takes found in all school shops. 



io A High School Course 

The The first tool that we use is the iron 

Plane jack plane. Since the rough stock from 
which we make this exercise is only 
about i2y 2 " long we shall use the jack plane for 
smoothing and for truing the surfaces. If we had 
to plane very long pieces we should use a fore 
plane; but since none of our work is very long, 
the individual kits need not contain a fore plane. 
A pattern maker has not mUch use for a smooth 
plane; because it is seldom that he wishes simply 
to smooth a piece without truing it. 

The best thing to do first, is to remove the bit 
from the plane, examine the parts, see how they 
work, and learn to put the bit back in place and 
lock the cap. Do this enough times so that you 
lose all fear of doing it and will not hesitate to do 
it, in the future, when the bit needs sharpening. 
Under the direction of the teacher learn to do it 
gracefully. This can best be accomplished by 
holding the plane with the bottom flat in the left 
hand and drawing the cap-cam up with the right. 
Do not let it snap as it may break off. To avoid 
a common mistake in replacing the bit, hold the 
plane on a level with the eye and see that the bit 
lies flat upon the frog. In order for the bit to lie 
flat, the little finger which forms one end of the 
"Y" adjustment, must penetrate the square hole 
in the plane-iron cap and the little disc on the 
lateral lever must engage the slot in the plane- 
iron. If you are careful about this, the cap-cam 
will go down easily. 



In Wood Pattern Making 



ii 




Fig. I 

In using the plane, most boys allow the rear of 
the plane to droop downward before the shaving 
begins (Fig. i), and when the plane has gone 
nearly the full length of the piece, and the knob 
is just passing the far end, they allow the front 
end to droop. This procedure will cause a hump 
or a hill to be planed on your piece. You can 
never plane a piece true, until you have learned 
always to keep the bottom of your plane parallel 
with your piece as it lies flat upon the bench 
(Fig. 2). 




Fig. 



Do not put the piece in the vise. If you push 
your plane straight to the bench-stop the piece 
will not dance around. The objection to putting 



12 A High School Course 

the piece in the vise is that too much time is lost 
opening and closing the vise to test the piece. 
You cannot afford to lose time in this course. 
Modern times demand efficiency from the workers ; 
so we may as well begin, right now, to omit 
unnecessary motions. 

Before planing, always run your finger lightly 
over the corners of your bit. If one corner pro- 
jects farther than the other, change it by shifting 
the lateral lever. Never take a deep bite. 

Sharpening The most disliked and at the 
the Bit same time the most necessary op- 

eration in wood working is sharpen- 
ing the tools. Too much stress cannot be laid on 
the importance of keeping the edge of the tools 
keen. Every boy should be provided with an oil- 
stone which is kept perfectly flat. In whetting 
a tool on an oil stone, try to maintain the bevel 
which is ground on the tool, raising the handle 
only enough to cause the edge to grind on the 
stone. Notice that one side of a paring tool is 
always Hat. Keep this side Hat on the stone and 
NEVER raise the handle or you will ruin the 
effectiveness of the tool. (Fig. 3.) 



^ , = crxo 



J j 0//-S?Ofre 6>0)t. 

1 "— 

Fig. 3 



In Wood Pattern Making 



13 



One lesson from the teacher, if he gives you 
personal attention, will prove that in a very few 
minutes, you can sharpen a tool, so that you could 
shave yourself with it ; and this accomplishment 
will make you so happy that you will never again 
try to work with a dull tool. 

Try- The next tool we use is a try-square. 

Square It consists of a blade and a beam. Always 
hold the square loosely in the right hand, 
grasping the beam at its mid point (Fig. 4), and, 
when squaring an edge or end, see that you press 
the beam firmly against the Face Side or Face 
Edge, allowing the blade to touch lightly the sur- 
face being tested. 

Pig- 5 




Fig. 4 



Fig. 6 




Gage 



The gage is an instrument that boys have 
difficulty in using. The great mistake is 
that they dig the spur into the wood so deeply 



14 A High School Course 

that the head will not slide freely along the Face 
Side or Face Edge. (Fig. 5). To avoid this, tilt 
the head over until the corner of the beam bears 
on the edge that you are marking and the pressure 
rides mostly on this corner, leaving only enough 
pressure on the spur to make a fine light hair 
line. (Fig. 6.) 

Scribe ' No pencil line is sufficiently accurate 
for this course and its use cannot be 
permitted. All laying off must be done with a 
scribe or knife, which must be sharp. The line 
must be deep and clean cut. It must be a hair 
line and we must work so accurately that by the 
expression "Working to a line" we mean splitting 
this hair line. These lines not only serve as a 
guide but also when planing off an end, prevent 
the little slivers from breaking out beyond the line 
and make a clean cut, square corner. Lay out 
everything with a knife accurately; then split 
the line and your work will be done correctly in 
one-fourth the time taken by the man who is too 
lazy to lay out the work, but takes off a shaving 
and then measures or tries the square and then 
takes another shaving, etc. This "cut and try" 
method does not make for efficiency. 

Back The chief difficulty in using this tool is 
Saw to get the cut started. It is a mistake to put 
the teeth flat on the piece and try to start 
the kerf parallel with the line. You must start the 
kerf on the far corner. Hold the piece tightly 



In Wood Pattern Making 



15 



against the bench hook with the left hand and 
then, without exerting pressure on the saw, draw 
the teeth across the corner at an angle to the 
surfaces, gradually lowering the handle as the 
kerf progresses, until the kerf is parallel to the 
line. (Fig. 7.) In these exercises you must never 
let the saw touch the line, but go very close to 
the line leaving only enough so that you can 
pare off a slight shaving with a plane or chisel. 




Fig. 7 



Block This little plane is used for planing end 
Plane grain on small blocks. Right here you 
should learn that, in order to cut wood 
smoothly, the tool must be given a lateral or side- 
wise movement, as well as a forward movement, 
otherwise you would squeeze the wood off, not 
cut it. To make this plain, imagine yourself cut- 
ting fresh bread. In this case you draw the knife 



16 A High School Course 

toward you as well as press it down. This 
Drawing Cut will be insisted upon in all block 
plane and chisel work, where the wood fibers must 
be severed. This is not necessary in cutting "with 
the grain." The block plane should be held al- 
most wholly within the right hand and the bit 
allowed to pass across the work at 45 ° to the 
edges and be drawn across the grain at the same 
time that it is pushed forward. The result should 
be a polished surface. 

Bevel This is like a square with an adjustable 
blade, so that, with it we may draw lines 
at other angles than 90 . 

Chisel It is foolhardy to attempt to use any 
but the keenest edged chisel on this work. 
You now know how to sharpen a plane bit. A 
chisel is much easier to sharpen. The same 
caution for whetting applies here : "Keep the 
back flat." 

Two other necessary precautions are : "Use 
the drawing cut," and "Keep the brake on." By 
the latter is meant that you must keep your left 
hand rigidly braced against the job and allow 
the tool to slide between the thumb and fore- 
finger, being ready at any time that the tool 
threatens to slip, to clamp the fingers together 
tightly and arrest the tool, before it slips out and 
splits away some of the wood that you didn't 
intend it should touch. 

In modern industrial management it has been 



In Wood Pattern Making 17 

found of advantage to issue instruction cards to 
mechanics, outlining in their proper sequence the 
operations which shall be performed on each piece 
of work. If this is an advantage to an experienced 
mechanic certainly it is of far more help to the 
inexperienced one. Below is an outline of op- 
erations for making the first exercise. 

INSTRUCTION CARD 

Exercise in Working to Scribe and Gage Lines with 
Saw and Chisel 

1 . Saw out a piece of rough white pine about 
1" X 2 J A" X 12^". 

2. True the Face Side with a jack plane and 
mark it. (To test the first side ; hold it up 
to the light parallel with the line of sight. If 
one corner appears high, plane it off and then 
test all over with the back of the square 
blade.) 

3 . True the Face Edge and mark it. (This must 
be squared with the face side. Hold the 
square as explained under "Square.") 

4. Plane the second side parallel to the Face 
Side. (Use gage lines to lay off the thick- 
ness.) 

5. Lay off one end with knife and square. Saw 
off very near to line and plane to line with a 
block plane. (Always clamp beam of square 
tightly to either Face Side or Face Edge, no 
other. Line must run all around the piece.) 



i8 



A High School Course 




E 












CO 



S 
CO 



^0 






In Wood Pattern Making 19 

6. Lay off the length and plane the other end. 

7. Plane off the second edge parallel to the Face 
Edge. (Using gage lines to get the width.) 

8. Measure along one edge and point off location 
of the lines for the gains. (Hold rule firmly 
against job, the divisions on the rule meet- 
ing the corner you wish to mark. Do not 
move rule each time you make a mark.) 

9. Draw the outlines of the gains. (Use the 
following tools : bevel, knife, square, and 
gage.) 

10. Saw just inside the knife lines in each gain, 
leaving very little to chisel off. 

11. Chisel out the bottoms of the gains with a 
i-inch chisel. (Use the drawing cut.) 

12. Chisel off the sides of the gains. (Use the 
drawing cut.) 

13. Stamp your name and section on end of piece 
with steel letters. (Stamp name on end grain 
on every exercise.) 

While the student is spending his shop periods 
making this exercise he should be spending his 
recitation periods acquiring a theoretic knowl- 
edge of the metal trades so that he can grasp the 
meaning of pattern making before he attempts to 
make his patterns. 



CHAPTER IV. 



MOULDING 



Moulding is of such importance to the student 
of pattern making that it is well to give him an 
insight into it, at the outset. If there is no 
foundry connected with the school, at least one 
moulding bench should be equipped and main- 
tained for demonstration purposes. 

The purpose of these pages on moulding is not 
to give a complete course in moulding, but to 
give enough data so that by following the direc- 
tions here given enough moulding can be done to 
demonstrate and make clear in the mind of the 
student just what happens to a pattern after it 
leaves the pattern shop ; to impress him with the 
importance of designing his pattern to suit the 
needs of the moulder. 

A mould in connection with the foundry busi- 
ness, is a shaped opening in the sand into which 
hot metal is poured in order to produce a casting. 
There are three classes of moulding: 
i . Loam moulding. 

2 . Dry sand moulding. 

3. Green sand moulding. 

Loam moulds are used for casting very heavy, 
plain pieces ; for example, a large, cylindrical drum 

20 



In Wood Pattern Making 21 

for hoisting. The loam is a mixture of old mould- 
ing sand and chopped straw, which, when 
properly dampened, makes a plaster-like mass. 
This is plastered on a circular brickwork support, 
built to the approximate diameter, upon a large 
iron plate. A sweep is revolved on a spindle 
erected at the center. This will sweep a smooth 
round layer of loam on the inside of the circular 
brickwork. The surface is now dried and the 
whole thing lowered into a pit and packed around 
with sand to strengthen it, so that the weight of 
the metal will not burst out the side. The smooth 
surface will form the face of the drum. The hub 
and arms may be made in dry sand forms. It will 
be noticed that no large pattern is used in making 
this mould ; but the pattern maker must be 
familiar with it, because he will be called upon to 
make the sweeps, or skeleton patterns, which may 
be required. 

Dry sand moulds are used for casting heavy 
work having considerable detail. A good example 
of this is a large steam engine cylinder, with its 
flanges, steam chest, exhaust outlet, etc. This 
mould is made in the same way as the green sand 
mould, which will be described in detail later ; 
but is thoroughly dried in an oven before pouring. 
The hot metalflowing in, causes less steam than 
in a green sand mould, and the hard caked mould 
offers more resistance to the heavy metal. 

Green sand moulds, by far the most frequently 
used, are used for making medium and small cast- 



22 A High School Course 

ings. The material used for making a mould 
is called moulding scmd and is found in nature. 
It is found at various places in the United States 
and brings a good price. It is a combination of 
sand and clay. The sand component serves as 
the heat resisting element and its open grain 
keeps the mould porous, so that the steam and 
gases may find their way to the vent holes. The 
clay component serves to bind the particles of 
sand together so that the mould may be made to 
retain its form. Obviously clay alone could not 
be used, as the heat of the metal would bake the 
clay around the casting, like a brick. The sand 
causes the dried matrix to crumble easily, so that 
the casting may be removed. 

There are two branches of green sand mould- 
ing: bench moulding and floor moulding. 

Moulds for machine parts, such as a lathe bed, 
lathe leg, bandsaw frame, etc., are made in large 
flasks on the floor. Small things, like water 
faucets, small pipe joints, etc., are moulded in 
small flasks, on a bench, for convenience in 
handling. 

We shall confine our attention to bench mould- 
ing; as it will serve to illustrate the principles of 
moulding which the student of this course must 
know. 

Tools Used in Moulding 

i. Flask: an open wooden or iron frame, in 



In Wood Pattern Making 23 

two or more sections, into which the sand is 
packed to make the mould. (Fig. 9.) 




Fig. p. Flask 

2. Cope : the upper half of the flask when in 
position for moulding. 

3. Drag: the lower half. 

4. Cheek: the intermediate portion when the 
flask consists of more than two parts. 

5. Mould board : a flat board on which the 
pattern and drag are placed for ramming up. 
(Fig. 17.) 

6. Bottom board : similar to mould board, on 
which the flask rests after rolling over. (Fig. 18.) 

7. Pattern : a near model or form by the use 
of which the mould is made. 

8. Rammer: an instrument used for packing 
sand into the flask. (Fig. 10.) 

9. Sprue pin : a cone shaped piece of wood 
which is rammed in the cope and which, when 



2 4 



A High School Course 



withdrawn, leaves a hole for conducting the metal 
into the mould. (Fig. n.) 





Fig. 10. Rammer 



Fig. ii. Sprue Pin 



10. Gate cutter: a bent piece of brass fitted 
with a handle, and used for cutting a channel 
leading from the bottom of the sprue hole to the 
mould. 

ii. Trowel: a flat, handled blade used for 
smoothing large surfaces. 



12. S 1 i c k e r : a 
double ended (leaf 
and spoon) instru- 
ment used for 
smoothing flat and 
rounded surfaces and 
for patching. (Fig. 

12.) 




Fig. 12. Slicker 



In Wood Pattern Making 25 

13. Corner slick: used for patching corners. 

14. Vent wire : a handled rod for piercing holes 
through the sand to the imbedded pattern to 
allow the air, steam and gas to escape. 

15. Draw screw: a threaded rod which is 
screwed into the imbedded pattern to act as a 
handle for pulling the pattern out of the sand. 

16. Swab : used for dripping water around edge 
of pattern to strengthen sand. 

Terms 

1. Ramming up : packing sand in flask. 

2. Sprue : opening through the cope left by 
sprue pin. (Fig. 14.) 

3. Gate: channel connecting sprue and mould. 
(Fig. 14.) 

4. Vents : openings provided for escape of 
gases, air and steam. 

5. Gases : formed by combustion of organic 
matter in the sand and by chemical reactions in 
the cooling metal. 

6. Rapping: gently tapping pattern to loosen 
it from surrounding sand. 

7. Drawing: removing pattern from sand. 

8. Pouring : filling mould with molten metal. 

9. Shaking out : dumping sand and casting out 
of flask after metal is hardened. 

Cores A hole through a casting or an internal 

cavity in a casting is made by using a 

core. A core is a body of sand projecting into, 



26 A High School Course 

or supported in the mould. The metal flowing 
into the mould will surround the core and after 
it cools the core sand can be cleaned out leaving 
an empty space. The core must have the same 
shape as the required cavity. This is accom- 
plished by ramming core sand into a core box. 
A core box is made of wood, its interior carved 
out to the same shape and size as the required 
cavity in the casting. (Figs. 15 and 20.) The 
core box is often made in halves, held together 
with dowel pins. The halves can be separated 
and the core dumped out. Large core boxes are 
built up. (Fig. 86.) It is the pattern maker's 
duty to make the core box. It is considered part 
of his pattern. 

Core sand is a combination of sharp sand and 
flour water, molasses water, or stale beer, the 
function of the last named being to bind the 
sand together so that it will hold its shape. The 
core is dumped from the core box upon an iron 
plate and placed in a core oven to bake. When 
baked, it is a hard mass that can be handled with- 
out fear of breaking. Core making is a separate 
trade. 

The hard core can be placed in the proper posi- 
ton in the mould. The pattern maker has antici- 
pated this and has provided means for marking 
the resting place of the core. This he accom- 
plished by making projections on the pattern 
(Fig. 13-3) the size and shape of which were 
determined by the size and shape of the hole 



In Wood Pattern Making 27 

or cavity in the casting, at the point where the 
hole or cavity cuts through the casting. These 
projections are called core prints. Therefore, 
core prints are projections on the pattern which 
mark out in the mould the resting place of the 
core. 

The core sand is easy to remove from the in- 
terior of a casting because the hot iron burns 
out the flour or molasses and destroys the bond, 
leaving the grains of sand free to flow from the 
cavity. 

Cores must be provided with vent holes to 
carry off the gases which form around them. 

Vertical cores are those which stand on end in 
the mould. (Fig. 14.) Their upper ends must 
be cone shaped and the cope core print is similarly 
cone shaped, so that, when the cope is lowered, 
the upper end of the core will be sure to enter the 
tapered hole formed by the cope print. This also 
serves to bring the core to a vertical position in 
case it had been leaning. 

Horizontal cores rest on two or more supports, 
one at each end. (Fig. 18.) 

Balanced cones have a free end projecting into 
the mould. In order to hold such a core in place 
the end which is supported is enlarged to be 
heavy enough to balance the free end. Such a 
core may also be held in position by chaplets. 

All the cores above are dry sand cores; but there 
there is another kind called a green sand core, 
which is formed right in the hollow pattern and is 



28 



A High School Course 













— * 












^ • 


.- 






1 1 





















Fig. 13 



In Wood Pattern Making 



29 



left standing when the pattern is withdrawn. This 

is spoken of as the pattern "leaving its own core." 

Fig. 13 illustrates what has been given above. 




Fig. 14. Section View of Mould for Bushing, Ready 
to Close 



Fig. 1 3- 1 shows! an ordinary bronze bushing. 
Fig. 13-2 shows a regulation shop drawing for 



30 A High School Course 

the bushing. In this case the pattern maker de- 
cides that the most convenient way to get the hole 
through the casting is to make use of a dry 
sand vertical core and to mould the pattern on 
end. Core prints are therefore provided to 
hold the core in place. Fig. 13-3 shows the 
pattern with its core prints. For convenience 
in ramming up this pattern, the cope, or tapered 
print, is not fastened to the pattern permanently, 
but is held in its proper place by a pin and can 
be easily removed. 

Fig. 14 is a cross section view, through the 
center of the mould for the bushing. The flask 
can be seen filled with sand in which the pattern 
has been imbedded and withdrawn, leaving its 
impression in the sand. The core is seen stand- 
ing on end, its lower end fitting snugly into the 
impression left by the drag print, and its upper 
end tapered to insure its entering the cope print. 

Notice the sprue running through the cope. 
The metal is poured into the sprue from the 
moulder's ladle, and finds its way into the mould 
through the gate. 

For heavy casting, the cope must be weighted 
or clamped down to prevent floating and a conse- 
quent leak between the flasks. 

Fig. 15 shows one-half of the core box in which 
the core is made. 



In Wood' Pattern Making 



31 




Fig. 15, Half of Core Box for Bnshin. 



Shrinkage It has been found that molten cast 
iron (C. I.) while cooling shrinks in 
size, until it is just at the point of solidification, 
when there is a slight expansion and then a 
further contraction, until it reaches the temper- 
ature of the atmosphere. 

This shrinkage occurs in all the dimensions of 
the casting and has been found to approximate 
Y% shrinkage per foot of dimension. If one 
wished to xast a bar of iron one foot long he 
would be obliged to make his pattern I2}£" long. 
The metal would be poured into a 12^" mould, 
but after all shrinkage had occurred the bar of 
cold metal would be 12" long. If it were de- 
sired to have the same bar one inch thick it 
would be necessary to make the pattern 1" plus 
1/96" thick because if the shrinkage is y in 12", 
in 1" it would be 1/12 X }i = 1/96", and so on, 
for every dimension. From the foregoing, it would 



32 A High School Course 

appear as if much laborious calculation is neces- 
sary in pattern making. This is not the case, 
however, as the pattern maker provides himself 
with a 

Shrinkage Rule 

This rule looks like a standard two-foot rule ; 
but if compared with a standard rule it will be 
found to be T /\' longer or 24.34" long. This length 
is divided into 24 equal spaces. Each space must, 
therefore, be 1 1/96 standard inches long. These 
are again subdivided into divisions corresponding 
to the eighths and sixteenths on a standard rule. 

One has only to measure every dimension on 
his pattern with a shrinkage rule to give the 
necessary increase in size to overcome the loss 
caused by shrinkage. 

Steel shrinks 3/16" per foot; brass (Br.) 3/16" 
per foot ; and other metals have different shrink- 
ages. The pattern maker must provide himself 
with a rule for each. 

Draft In order to make it easier for the 
moulder to draw a pattern from the sand 
the pattern maker tapers the vertical sides of the 
pattern. This taper is called draft. The custo- 
mary amount is Y%" per foot in height. Where 
the height is only an inch or two, the taper cannot 
be measured, therefore the nearest one can come 
to laying down a rule for it is to say that only 
a slight taper is necessary. 



In Wood Pattern Making 33 

Parted A pattern of cylindrical shape is dif- 

Patterns ficult to remove from the sand. Here 
again the pattern maker makes it 
easier for the moulder by making the pattern in 
halves, loosely held in their proper relation to 
each other by dowel pins. This is called a parted 
pattern. The half containing the dozvel pins is 
called the cope half and is moulded in the cope 
flask. The half containing the dowel pin holes is 
moulded in the drag flask and is known as the 
drag half of the pattern. The pipe joint (Fig. 16) 




Pipe Joint 



spoken of in the following chapter requires a 
pattern of this class. 

Most parted patterns are parted on their center 
line. However, patterns whose shape is not sym- 
metrical must be parted on some other line de- 



34 A High School Course 

termined by the direction of the draft on either 
side of this line. 

Though it is customary to part cylindrical pat- 
terns, it is often found expedient to make the 
pattern solid and allow the moulder to cut his 
parting with a trowel. That is, he imbeds the 
whole cylinder in the sand and then cuts the sand 
away, down to the center line, rams up the cope 
and allows the cope to lift off the impression of 
the upper half of the pattern. The pattern now 
has nothing to impede its withdrawal from the 
sand. This will readily be understood after the 
student has seen a demonstration in moulding. 

Making a Mould for a Small Pipe Joint 

The sequence of operations to be followed in 
making this mould follows : 

i . Place the drag half of the flask, pin holes 
down, on the moulding board. 

2. Place the drag half of the pattern, flat side 
down on the moulding board inside of the 
flask. (Fig. 17.) 

3. Place the sieve on top of the flask, fill with 
facing sand, and shake until the pattern is 
completely covered. (This removes any 
lumps which would cause rough spots on the 
casting.) 

4. Shovel common sand on top of this until 
the flask is heaped full. 

5. Pack the sand hard with the rammer. (Use 



In Wood Pattern Making 35 

the peen to get close to the edge and use the 
butt in the center.) 

6. Strike the sand off level with the top of the 
flask, with a straight edge. 

7. Make the vent holes. 

8. Sprinkle a little loose sand over the top and 
rub down the bottom board to a good bearing. 

9. Clasp both boards and flask together firmly 
and roll over. 

10. Remove the moulding board. 

11. Fit on the cope half of the flask. 

12. Fit on the cope half of the pattern. 

13. Sprinkle on parting sand. 

14. Push the end of the sprue pin into the drag 
sand allowing the main body of the pin to 
extend upright through the cope. 

15. Fill the cope flask full of sand, ram up and 
strike off. 

16. Make vent holes. 

17. Remove the sprue pin. 

18. Place the moulding board on top of the cope. 

19. Carefully lift the cope, turn over and put 
aside. 

20. Drip water around the edge of the pattern 
with a sponge or swab. 

21 . Cut the gate from the sprue to the pattern. 

22. Insert the draw screw, rap and draw both 
halves of the pattern. 

23. Dress up any portion of the mould which 
may have been accidentally broken. 

24. Place the core in position, its ends resting in 
the core print spaces. (Fig. 18.) 



36 A High School Course 

25. Close the mould. 

26. Pour in the melted metal. 

27. When sufficiently cooled, shake out. 

28. When cold, chip off the gate, clean the sand 
off the outside and clean the core sand out 
of the inside. 

We now have what is known as the casting. 
(Fig. 16.) 




Fig. 17. Pipe Joint Pattern in Flask, Ready to 
Ram Up 



In Wood Pattern Making 



37 




38 



A High School Course 



■y •• .-. ••.«•:•.! 






» 
» 



Fio-. /p. Cor^ /or £/^ Fi^^ /omi 




Fig. ,?o. //a// 0/ f/i£ Cor£ Box for the Pipe 
Joint Core 



CHAPTER V. 



PATTERN MAKING 



Pattern making is the art of making forms, or 
near models, by the use of which sand moulds 
are made. 

An extended range of thought, skill, and ex- 
perience is necessary for efficient pattern making. 
The pattern maker must possess a greater variety 
of talents than the mechanic of any other branch 
of the metal trades. Owing to the great field 
which it covers, a course in pattern making offers 
an unusual opportunity for mental development 
in addition to training the hand. 

Lumber The material from which ordinary 
wood patterns are made is white pine. 
The best quality of white pine for the pattern 
maker's use, is known as Michigan white pine. 
It grows in Michigan and the adjoining northern 
states. It grows in immense trees, from one 
hundred to two hundred feet in height and two 
to four feet in diameter. It is soft, very light 
in weight, of almost a cream color, is durable, 
warps little as compared Avith other woods, can 
be easily worked with wood worker's tools and 
usually has a very straight grain. These proper- 
ties make it very desirable for pattern making : 

39 



40 A High School Course 

but owing to its growing scarcity it is becoming 
very expensive. Therefore, if you are given white 
pine from which to make your patterns, be very 
economical in its use. Be sure to learn the dif- 
ference between white pine and the other soft 
woods usually found around a manual training 
shop, and use only white pine for your patterns, 
if you want them to retain their original shapes. 

Patterns which are to stand extraordinary use, 
that is, which are to be used hundreds of times 
in the foundry, are made of hard woods, such as 
mahogany, cherry or walnut, all of which are easily 
worked, considering that they are hard woods. 

Lumbering and sawmilling should be inter- 
esting to a student of this course and much inter- 
esting reading can be had on the subject. The 
seasoning of lumber is of such importance that 
we must give it some attention in these pages. 
By seasoning we mean "Drying out the sap." 

When trees are felled they contain 50% by 
weight of moisture, due to sap which circulates 
through the tree. By a long period of drying in 
air, in a sheltered place (two years for a 1" board), 
this moisture can be reduced to 12 or 15%. As 
the wood loses its moisture, it becomes consider- 
ably smaller : in other words, it shrinks. There- 
fore, if we wish to make a wooden object which 
is expected to retain its original size and shape, we 
must be careful to use well seasoned lumber. 

The moisture in a 1" board can be reduced to 
5 or 6% in a few days in a dry kiln (a dry kiln is a 



In Wood Pattern Making 



41 



steam heated compartment heated to about 
180 .), but when brought out of the kiln it absorbs 
moisture from the atmosphere until it contains 
the usual 12 to 15%. The amount which it con- 
tains varies with the moisture in the atmosphere. 
This explains why wood continually changes and 
why furniture often creaks, seemingly without 
cause. 

Certain laws govern these changes and the 
pattern maker must familiarize himself with them. 
He must anticipate what changes will occur and 
build his pattern so as to minimize the ills. Thus 
framing up a wide flat pattern (Fig. 21) and stav- 
ing up a large round pattern (Fig. 22) would be 
resorted to, in order to do away with a wide cross 
grain and its consequent shrinkage; and open 
joints would be resorted to, in order to distribute 
the shrinkage evenly; and battens (Fig. 23) would 
be used to hold a curling piece straight. In the 




Fig. 21. Large Flat Pattern Framed Up. Open 
Joints Between Boards Distributes Shrinkage 
and Swelling Equally 



4 2 



A High School Course 



latter case, as the battens form no part of the 
casting, the moulder fills them up. Instructions 
to the moulder fill up must be painted on the 
battens with black shellac. 




7 



Fig. 22. Half of a Large Cylinder, Staved or 
Lagged Up. 




Fig. 23. Battens 



If wood is allowed to lie flat on the bench in a 
warm room its upper surface will dry out and 
contract, causing an upward curl. (Fig. 24.) 

If a board is allowed to lie flat on the bench in 



In Wood Pattern Making 43 

a damp atmosphere, the exposed side will absorb 
moisture from the atmosphere and swell while 
the under side is protected and remains the same 
size, causing it to curl concave down. (Fig. 25.) 



Fig. 24 



Fig- 25 



Fig. 26 

The old wood at the heart of the tree will dry 
out less quickly than the newer open grain sap 
wood near the bark ; so a board has a tendency to 
curl away from the heart. (Fig. 26.) For this 
reason, a pattern maker, in making a job which 
is very particular, would select a board which is 
sawed radially with the log, or a quarter sawed 
board. To determine a quarter sawed board, one 



44 



A High School Course 



must inspect the annual rings on the end of the 
board. (Fig. 27.) 




P/a//? Sawed 

Fig. 27 



Quarter 



The porous, end grain of a board dries and con- 
tracts more quickly than the solid mass of wood, 
causing a strain and finally a split. This is called 
a check and may be prevented by shellacing the 
end, immediately after it is trimmed off. 

The unit of board measure is the board foot. 

Drawings Drawings are representations of the 
finished iron object. They are made 
for the machine shop, to guide the machinist in 
cutting, boring, planing and fitting, so as to pro- 
duce an object embodying the general require- 
ments. No drawing of the pattern is furnished 
for the pattern maker. The pattern maker gets 
what information he can from the machine shop 



In Wood Pattern Making 45 

drawing and then makes, from his imagination, 
some form in wood, which the workman following 
him can use to produce the required object. The 
pattern often does not look like the desired object, 
but bears only a general resemblance to it. Draw- 
ings are seldom made full size. The pattern 
maker lays down a full size drawing of the pat- 
tern on a board, making the lines with a knife 
instead of pencil. 

Drawings are seldom correct. Dimensions are 
often changed on the blue-print, without making 
a corresponding change in the lines ; therefore 
keep to the given dimensions and scale the draw- 
ing only when the draftsman has omitted the 
dimensions. The blame for a mistake then rests 
upon the draftsman. 

The style of drawing used in shop drawing, 
is called orthographic projection. Practically all 
high schools that have a course in pattern making, 
also have a course in mechanical drawing; there- 
fore instruction in drawing will be left to the 
Mechanical Drawing Department. 

Allowances There are three additions not 
in Pattern called for on the drawing, which 
Making the pattern maker must put upon 

the pattern; namely, finish, shrink- 
age, and draft. 

Finish is an addition of %" of extra metal on 
all surfaces which are to be machined smooth in 
the machine shop. (Fig. 29.) Surfaces which fit 



4 6 



A High School Course 



together, slide on one another, or revolve one in 
the other, are treated in this manner. Such sur- 
faces are indicated by a little "f" on the draw- 
ing. The "£" crosses the line representing the 
surface to be smoothed. (Fig. 28.) 




C q/incfer Poire/ 1 . 
CasfIro/7 . 

Fig. 28. Shop Drazving of Cylinder Cover 



In Wood Pattern Making 47 

Shrinkage is an addition of y%" per foot to over- 
come the loss caused by the shrinkage of the 
metal in cooling. This shrinkage of metal is ex- 
plained under Moulding. 

Draft is a slight taper (%" per foot) on the 
vertical sides of patterns to facilitate the with- 
drawal from the sand. (Fig. 29.) 



1 I Ji Tfos /tfti our wtfh fJre cape.. J 



*c 



^ fa;*/, v : — ----- r 

Fig. 2p. Drawing of Pattern for Cylinder Cover 
Showing Allowances. Measured with the 
Shrinkage Rule 

The pattern maker's drawing must show that 
these allowances have been added. A sample 
shop drawing and a pattern drawing are given 
in Figs. 28 and 29. Students must follow this 
form. 

Fig. 28 is a sample of the kind of drawing- 
usually furnished to the pattern maker. It is a 
picture of the finished cast iron object. 

Fig. 29 is a sample of drawing made by the 
pattern maker from information given by the 
shop drawing plus the allowances which he 
knows he must add. This is a picture of the 
Pattern. Note the difference. Frequently as in 
this case, a cross-section only is required. The 
pattern maker omits the plan view and dimen- 
sions, but makes the drawing full size. 



CHAPTER VI 

BENCH WORK 
Pattern No. i, Introducing Finish, Shrinkage and Draft 

The drawing opposite represents a machine 
shop exercise in chipping and filing. In order 
that the machine shop student may produce this 
object, he must be supplied with a block of cast 
iron of the approximate shape. The foundry 
furnishes this block; but in order to produce it, 
the foundry must be supplied with a pattern. 
The pattern shop is responsible for the production 
of the pattern. 

The first thing to do in making a pattern for 
this, is to make a drawing of the pattern. As 
you have already learned, it will be somewhat 
different from the Machine Shop drawing. Begin 
by laying down the center lines, and then, make a 
full size copy of the Machine Shop drawing. (Side 
view is sufficient.) If you use a shrinkage rule 
the shrinkage will be taken care of. Notice that 
the drawing calls for C. I. ; therefore you must 
select the cast iron, or y% per. foot shrink rule. 
Next examine the drawing and pick out the 
"f's." The surface which the "f" crosses must be 
finished or filed off in the machine shop. On 
these surfaces we must add y%" . This constitutes 

48 



In Wood Pattern Making 



J 



z 



/ 



49 



rrr 



LJ_ 



/ 



5. 
8 



p3" 



¥■ 



■?- 



7\1 



+ 






J 



P H* 



*-T? 



4S 



h 



y 



CI — 



/i- 



<i* 



<% 



Fig- 3°- Machine Shop Exercise 
and Filing 



Chippini 



the allowance for finish. Therefore draw lines 
parallel to these surfaces and y$" from them. It 
will be noticed that, when y% is added on each 



5o 



A Hizh School Course 



side of the y% wide slot, only y%" space is 
left. No strip of sand y% wide would stand the 
strain when the cope is lifted off. It would break 
off; therefore, the pattern maker decides it is 
best not to bother with it and makes the surface 
flat, leaving the whole slot for the machinist to 




Fig. 31. Drawing of Pattern Shozving Allowances 

chisel out. Next consider how the pattern is to be 
drawn from the sand. You decide that the small 
block should be on the under side, the draw screw 
being screwed into the top of the larger block. 
Draw the taper on the vertical sides accordingly, 
remembering that this is an addition. This is the 
draft. The chamfer around the top would cause 
the moulder to cut a parting. Therefore, it is 
best to leave it out; as the machinist can easily 
chisel the chamfer. The pattern is now very 
simple. The drawing here given is not according 
to dimensions, and is only given as a hint as to 
how the pattern will look. The student must 
make a full size drawing according to directions 
above. 



In Wood Pattern Making 



51 



Now, by simply measuring your drawing, you 
can avoid further calculation. 

Next consider the quickest way to build up 
the pattern. In this case, you would nail and 
glue the two blocks together. Now get out the 
two blocks, using the operations numbered one 
to seven of Ex. No. 1. Instead of making the face 
edge square with the face side, we slant it slightly 
for draft, then fixing the bevel at this slant, we 
mark of! the ends with the same draft. Do this 
on all patterns. 

Now find the center of the smaller side of the 
large block and, with a pair of sharp dividers, 
strike a circle at this center. The diameter of this 
circle is to be the width across the large side of 
the small block. Circumscribe a square about 
this circle, as in illustration. (Fig. 32.) This 




Fig. 32 



will locate the small block exactly in the center 
of the large block. Now put a spot of glue on 
the small block and place it on the square and 



52 A High School Course 

drive two i 1 /^' nails through the large block into 
the smaller one. The pattern is now ready to 
be sand papered and shellaced. When sand 
papering, be careful not to round off surfaces and 
corners. 

Shellac Shellac is a varnish made from shellac 
gum dissolved in alcohol. Several 
coats of it (three or four) are applied to every 
pattern, with a varnish brush, and cause a smooth 
glossy finish. 

The purpose of the shellac is not to make the 
pattern beautiful ; but to cause a smooth surface 
which will draw easily from the sand and to make 
a moisture proof covering to help prevent the 
wood from absorbing moisture and becoming 
distorted. 

Never have a shellac brush dripping full. 
Shellac only half of the pattern at a time. To 
avoid finger marks, let one half dry thoroughly, 
before catching hold of it to shellac the other 
half. Each coat must be rubbed down, after it 
becomes thoroughly dry. Use smooth, wornout 
sand paper, No. o. Avoid the corners and do not 
rub so hard that you scratch off the shellac. A 
few light strokes will suffice. 

PATTERN NUMBER TWO 
Introducing the Green Sand Core 

This is a pattern for a machine shop exercise 
in chipping, filing, and fitting. The drawing 



In Wood Pattern Making 



53 




54 



A High School Course 



shows a square plug fitted into a square, hole. 

Two patterns would be necessary, one for each 
part; but the pattern for the plug has no value 
as an exercise and may be omitted. The square 
hole in the other piece, may be accomplished by 
cutting a square hole in the pattern and giving 
it the proper draft, so it will leave its own green 
sand core. Owing to the difficulty in moulding 
a small bar of sand, more draft than usual is al- 
lowed inside a hole. Use 1/16" draft on each side. 



Hi 


r 


llfll 











Fig. 34. Section of Pattern Showing Allowances 
Instruction Card 

1 . Lay down drawing as before, and add allow- 
ances. 

Plane up blank to the required size as usual. 
Lay out square hole in center of top and 
bottom by circumscribing a square about the 
proper size circle, as you learned in Pattern 
No. 1. Make lines with a knife. 
Bore 1" hole within the square. 
Saw to corners with a keyhole saw. 
Chisel sides of hole with y^' chisel, taking 
small bites and using drawing cut when 
possible. 



2. 

3- 



In Wood Pattern Making 



55 



Sand paper the hole by wrapping sand paper 
tightly around a sharp square-cornered stick 



» 1 | i 

wo ; i i 



t — r 



i ! 
i i 

J-JL 



a 



a 



<o 



q e 






./ :/ 



■/■ 



/ 












a 









s 



to 






56 A High School Course 

about y 2 " square and 10" long, using it as a 
file, being careful not to rock it. 
8. Shellac the pattern. 

Brace The r" auger bit used in this exercise, 

and Bit may be recognized by a figure "16" on 
the tapered shank. Place the bit in 
the brace and hold block in vise. Bore half way 
through and then turn block around and bore 
through from the other side to avoid breaking 
out chips. 

PATTERN NUMBER THREE 

Calling Attention to the Fact That Small Holes Under 

3^" Diameter Are Not Cored— Pattern for M. S. 

Ex. in Fitting and Drilling 

The blue print furnished is an assembly draw- 
ing. Since both details are exactly alike, only 
one pattern is necessary. Simply supply the 
machinist with two castings from the same 
pattern. A new feature is the manner of marking 
the finish. (Note the "f all over.") 

The pattern maker at once decides that the 
y 2 " diameter hole called for is too small to core 
out; as the slender bar of sand would break off 
when the pattern is drawn ; so he leaves it for the 
machinist to drill out. 

Proceed with this pattern exactly as you did 
with the others. In this case, a plan and an end 
view of the pattern should be prepared.* 



*Student should now be able to make a drawing of this pattern 
without a specimen Rawing. 



CHAPTER VII. 



WOOD TURNING. 



Students should become familiar with the wood 
turning lathe and turning tools, before they at- 
tempt to make a pattern on the lathe. A few 
simple exercises on the lathe will give sufficient 
knowledge, for this course. The lathe is a simple 
machine and easy to operate. A demonstration 
by the teacher is sufficient to familiarize the 
student with the names and functions of the 
various parts. The real difficulty to the beginner, 
is in handling the turning tools. 

Wood Turning Exercise No. i 

Cylinder Students should first turn a plain 
cylinder, like that in the accompanying 
drawing (Fig. 36). 




Fig. 36. Plain Cylinder 

Select a piece of poplar, gum, or pine wood 
about 2" X 2" X 8" : mark the centers of the ends 

57 



58 A High School Course 

and drive the spur center into one end. Slip the 
spur center into the spindle in the head stock ; 
bring the tail stock up, so that the cone center 
touches the center of the other end ; fasten the 
tail stock; and force the cone center into the 
piece, by revolving the hand wheel. Loosen the 
cone center slightly and oil it to keep the pieces 
from screeching when it revolves. Move the rest 
up close to the job and fasten it. Revolve the job 
by hand to be sure that it clears the rest, before 
turning on the power. 



sc 



Fig. 37. Roughing Gouge 

Grasp the handle of the roughing gouge (^4" or 
larger) firmly in the right hand and with the 
fingers of the left hand press the rounded back of 
the tool upon the rest, allowing the hand itself 
to bear firmly against the rest. Feed slowly in 
until the tool begins to cut, and then move it 
slowly along to the right, until the end of the 
piece is reached. If cutting from left to right, roll 
the tool slightly to the right, so that the shaving 
will come off between the center of the point of 
the tool and its right hand edge. This gives a 
smooth cut. Otherwise you get a scraping effect 
which causes a rough surface. One can cut 
equally well both going and coming, providing 
the angle of the tool is changed with the change 
in direction. 



In Wood Pattern Making 



59 



Take cut after cut until the piece is perfectly 
round and then lay aside the gouge and take the 
turning chisel {%" or larger). 



^s 



sar=o 



Fig. 38. Turning Chisel 

Lay the chisel flat upon the rest and the job 
and begin to raise the handle cautiously, until it 
begins to cut, at the point indicated in Fig. 39. 




Fig. 39. Cutting With Turning Chisel 



Fig. 40 also gives an idea of the position of the 
tool ; though this cut shows the tool when the 
handle is raised too much. The under bevel must 
be kept in sliding contact with the cylinder, or 
the tool will dig in. The point must also be kept 
clear, as indicated in Fig. 40, or the tool will 
dig in and ruin the job. 

Take a fine shaving off the full length, starting 
near the left hand end and moving toward the 



60 A High School Course 

right, until the end of the piece is reached ; then 
reverse the tool and, returning to the starting 
point, cut toward the left. Do not try to start at 



**■ Point" rnt/stbe. 




Fig. 40 

the end. The bevel will have nothing to slide on 
and the cutting edge will dig in. Stop the lathe 
frequently to test with a pair of outside calipers, 
until the cylinder is of the correct diameter ; 




Fig. 41. Outside Calipers 



In Wood Pattern Making 



61 



then smooth the ends, holding the chisel as shown 
in Fig. 45. Do not sandpaper or shellac the turn- 
ing exercises. The surface will be very smooth 
if you have followed directions and used SHARP 
TOOLS. 

Sharpening The student should learn to 

Lathe Tools sharpen all lathe tools, whether 
chisels or gouges, with a coarse slip 
stone. Grasp the blade of the tool in the left 
hand, allowing the handle to pass under left arm. 
Hold the slip stone in the right hand, the thumb 
touching one end and the fingers the other. The 
hand is, in this way, shielded by the stone and 
there is little danger of the tool slipping off and 
cutting the hand. Rub the slip stone over the 
tool, giving the wrist free movement, and en- 
deavor to maintain the bevel ground on the tool. 
Do not snub it off. 



Wood Turning Exercise No. 2 



7- 



*" 








/ s 


J - 








If 
( 1 













& 



/ 



Fig. 42. Beads 



Beads 



First prepare a plain cylinder, similar 
to the one described in Ex. 1 ; then lay 
off pencil line around the piece, Y^' apart. Be- 



62 



A Hizh School Course 



ginning with the second line, make a cut with the 
point of the chisel at each alternate mark. Using 
the first mark as a center for your bead, and with 
the turning chisel in position for cutting, begin 
to roll the cutting edge deeper into the wood, 
swinging the handle up at the same time. In this 
way, a smooth round half bead can be formed. 
Reverse the tool and repeat the operation, for 
the adjoining half of the next bead, and continue, 
until all are nicely rounded and of an even depth. 
For very small beads the point of a small chisel 
may be used instead of the heel, as stated above. 

Wood Turning Exercise No. 3 




Fig. 43. Coves 



Coves Make a cylinder, as before, and lay off 
the spaces for the coves. Make a cut at 
each line with the point of the chisel. Coves are 
turned out with a gouge. Use a y% gouge for a 
y cove. To start the cut, rest the edge of the 
gouge on the tool rest, allowing the cutting edge 
to enter the chisel mark, at right angles to the 
axis of the job, and, as you press the tool deeper, 
gradually roll it, at the same time lowering the 



In Wood Pattern Making 63 

handle. This will raise the cutting edge and pre- 
sent the proper cutting angle to the wood. Next 
reverse the tool and take a cut from the opposite 
side of the cove, repeating these operations until 
the cove is semi-circular in form. If the tool is 
sharpened frequently, very smooth surfaces will 
result. 

Wood Turning in Pattern Making 

The methods given above are distinctly wood- 
turner's methods. Very few pattern makers can 
use the turning chisel and gouge in this manner. 




Fig- 44 

The pattern maker uses scraping tools almost 
entirely. (Fig. 44 illustrates the scraping tool in 
use.) The reason for this is that the scraping tool 
is much easier to control than the cutting tool. 
The pattern maker must be very careful to get 
the exact dimensions and cannot afford to take 



64 A High School Course 

the risk involved in using the cutting tools. His 
work is frequently of large diameter. For this 
kind of work the regular turning chisel is un- 
suited. He uses the roughing gouge in the usual 
manner. He finishes with a square point chisel 
which is similar to a paring chisel except that it is 
longer and stronger. To turn out coves he uses 
a round point tool. 

It is a great advantage, however, to be able to 
use the turning chisel and gouge ; for more 
slender work can be done with them than with the 
scraping tools. Moreover, the latter cause con- 
siderable chatter. The turning tools should there- 
fore be used when turning patterns of small 
diameter. 



CHAPTER VIII 



TURNED PATTERNS 



Bushing The Bushing (Fig. 13) is turned be- 
tween centers. This is to be made of 
bronze; therefore select the 3/16" shrink rule. 
Proceed as in turning the cylinder. In order to 
turn the steps forming the flange and the core 
print, push the tool along in the ordinary manner, 
until it is very near the mark ; then begin to swing 
the handle around, until the tool is at right angles 
to the axis of the job. The heel will then fit 
closely into the corner. (Fig. 45.) 




Fig. 45. Cutting Steps with Skew Chisel 
65 




66 A High School Course 

The pattern and core print must be tapered 
very slightly to the right for draft. The cone 
print must be turned separately. 

Its length should be about' %" 
and the diameter, at the small 
end, about one-half of the diam- 
eter at the large end. The pin Fig. 4&- 
may be about y 2 " diameter. Cone Prmt 

After the pattern has been turned to size and 
sanded, a coat of shellac should be applied and 
the pattern removed from the lathe. The ends 
should then be sawed off with a back saw, while 
the piece is held in the bench hook. Leave 
enough of the end on so that it can be smoothed 
off with a chisel. Find the center of the cope end 
with a center square and bore a y^' hole, to re- 
ceive the cone print pin. 

Give the whole pattern several more coats of 
shellac, rubbing it smooth after each coat is 
thoroughly dry, and finally apply black shellac 
to the core prints. 

The bushing is moulded on end because it is 
short, compared with its diameter ; but when a 
pattern is several times greater in length than in 
diameter, it must be parted for convenience in 
moulding; since such a pattern would be moulded 
horizontally to avoid a deep flask. * 



* For the purpose of this exercise the core box may be 
omitted. 



In Wood Pattern Making 



6 7 




to 






68 A High School Course 

To Shellac on the Lathe 

Scrape most of the shellac off the brush on the 
edge of the container, and rub the shellac well 
into the wood. Do not have streams of shellac 
dripping off. Do not put the lathe in motion until 
the shellacing is completed. Then start the lathe 
to cause the shellac to dry quickly. With the 
lathe in motion rub the wood lightly with worn- 
out sand paper. When smooth remove it from 
the lathe. Shellacing should be finished at the 
bench. 

A Parted Pattern 

Hollow A pattern for the hollow cylinder 

Cylinder (Fig. 47) would necessarily be a 
parted pattern. The hole through the 
cylinder would be accomplished by using a hori- 
zontal core ; therefore core prints must be pro- 
vided on the ends of the pattern. 

To make such a pattern proceed as follows : 
Get out two rough blocks, as shown in the illus- 
tration (Fig. 48). Plane off one side of each and 
fit them together. Make a perfect fit. The two 
blocks should be as long as the cylinder is to be, 
plus finish, plus the core prints on each end, (for 
patterns such as shown, prints should be about 
i34" long)* pl us X J^" at each end for screws, plus 
y 2 " at each end for cutting off and, when fitted to- 
gether should form a parallelopiped large enough, 
so that a cylinder of the desired size can be turned 
out of it. Next calculate how far on each side of 



In Wood Pattern Making 



6 9 




7° 



A Hizh School Coarse 



the center (lengthwise) the core prints will be, 
and drill doAvel pin holes, as shown (Fig. 49) 



Ml 






.-.J-^ ssw 



:::£5$> 



rt.< w: 







In Wood Pattern Making 71 

through the top piece and j4" into the bottom 
piece. Taper the ends of two dowel sticks and 
drive them in so that the taper just comes through 
the top piece. Bore screw holes (b Fig. 48) a 
little larger than the head of the screw you intend 
to use. You want the head to sink below the 
surface about J4" so that your tools don't strike it 
when turning. This is called counter boring. 

.Drill holes slightly larger than the smooth 
shank of the screw, as shown at h (Fig. 48). Drill 
no screw hole into the second block. Screw the 
blocks tightly together.* Punch the centers in 
the ends, being careful to get them exact. The 
center must be on the parting-. Drive in the spur 
center. Hold the piece in the vise for this opera^ 
tion, so that the point on the spur center does not 
force the blocks apart. Now turn the pattern up 
on the lathe, in the usual manner, until you have 
reached a point, as illustrated by Fig. 49. Then 
sandpaper and shellac the job once, and remove it 
from the lathe and with a bench hook and back 
saw, saw off the ends, take out screws, and return 
them to their proper box. Do not saw too near 
the core print, as you must now take a sharp 
chisel and chisel the ends smooth, being careful 
not to chisel off the draft which you should have 
turned on, as shown at draft, (Fig-. 49). Now 
finish the shellacing, painting the core print 
black and also the outline of the core on the 
parting of the drag half of the pattern. 



* Corrugated steel fasteners could be used ; but screwing 
blocks together is a more valuable exercise. 



J2 A High School Course 

The Core Box 

The cylindrical hole through the casting is 
formed by a horizontal core. The core must be 
moulded in a core box, which the pattern maker 
must furnish. To make it, fit and pin two blocks 
together. For this job, the blocks should each be 
roughly 8" X 4" X ij4". The pin holes should 
be bored through one block into the other and 
taper ended dowel pins fastened into one of the 
blocks, as was done in the pattern. When the 
blocks are pinned together, dress off one edge 
square with the joints and use this as a face edge 
for squaring the ends, which should next be 
dressed off. The length of the core box is always 
made a little less than the over-all length of the 
pattern, so that the moulder will have no difficulty 
in setting the core into the mould. 

Gage center lines on the joints and ends of the 
blocks, using the face edge as a guide. (See note, 
Fig. 50). With sharp dividers and using as cen- 



Loi/ out core 60^ m'M 




o Dowe/pm holes 



clean cut lines. 



Ce/rJer//he g&yec/ 
Porajfe/ fo face /Tcfye 




Fig. 50. Layout of Core Box 



In Wood Pattern Making 



73 



ters the intersections of the center lines with the 
joints, strike clean cut circles on the ends. Con- 
nect the circles with clean cut lines. All the wood 




so 

.*> 
8 

CO 






OSj 



74 A High School Course 

within the circle must now be removed. Run 
several saw cuts from the joint to the circle and 
gouge out the wood with an inside ground gouge 
of suitable radius. To insure gouging the same 
diameter hole, all the way through, you must 
make tests with a straight edge, as shown 
(Fig. 51). When all the lumps are removed the 
straight edge will ride on the end circles. A 
templet, as shown, can also be used. 



CHAPTER IX 



GOUGE AND TEMPLET WORK 




Fig. j2. Drip Cup 



The The most convenient way to test the 

Templet depth and shape of the bottom of the 
drip cup, is to employ a templet. A 
templet is usually made of wood, about y%" thick, 
cut to desired shape and used to test irregular 
surfaces. 

75 



7 6 



A High School Course 



DRIP CUP 
Instruction Card 

1 . Plane a piece of wood to the thickness of 
the drip cup, but longer and wider. 

2. Plane off one end, giving it some draft. 

3. Lay off the outline of the cup on the face 
and ends. (Fig. 53.) 




Fig. 53. Layout of Drip Cup 
4. Make a templet for testing the inside. 



(! 1 =7 

I J _l 



Fig. 54. Templet for Inside 

5. Gouge out the inside. Use an inside ground 
paring gouge of suitable radius, along the 
straight lines, and an outside ground or a 



In Wood Pattern Making 



77 



6. 
7- 



spoon gouge, at the curved end. Clean out 
all lumps, until the templet can be slid along 
without riding on a lump, and cut deeply 
enough, so that the ears of the templet ride 
on the edges of the cup. To test the curved 
end, revolve the templet on the center of the 
curve. 

Sandpaper the inside perfectly smooth. 
Round off the bottom by planing down 
to the curves drawn on the ends. (Fig. 55.) 




Fig. 55> 

8. Make a templet for rounding off the end. 

9. Saw off the end to the curved line and work 
it to shape with a chisel or spoke shave, 
testing it frequently with the templet. To 




Fig. 56. Templet for Outside 

keep the vise from mashing the job during 
this operation, shape a block to fit the inside 



y8 A High School Course 

in order to get the pressure on the bottom 

instead of on the edges. 
10. Make the strip which fits across the other 

end and nail and glue it fast. See that the 

draft is correct. 
In moulding this cup, the hollow is formed by 
a green sand core which hangs in the cope when 
the cope is lifted off. 

Built Up Work, Fillets, and Tail Prints 

Rail Up to this point, our patterns were of 

Stop such a nature that they were easily cut 
from one piece. In most cases, however, 
it is more economical to build the patterns of 
several pieces. 

To make the rail stop, get out two pieces y%" 
thick and the specified shape for the web, and pin 
them together (Parted Pattern). Then get out 
the pieces that form the base and the curved part, 
and glue and nail them fast on each side of the 
web. 

Fillets Examine any rough casting and you 
will find few sharp corners. Whenever 
possible corners are rounded. The reason for this 
is that, when iron cools, the crystals arrange 
themselves at right angles to the surface and, if 
a corner is left square, they join imperfectly at 
the corners; so sharp corners must be avoided. 
To save much carving, leather fillets have been 
devised which can be glued into the sharp corner. 



In Wood Pattern Making 



79 




8o 



A High School Course 



The leather fillet is a strip of leather of triangular 
cross section. To apply leather fillets, begin by 
cutting them to proper lengths, laying them flat 
upon a scrap piece of wood and applying glue. 
Allow the glue to dry, until it is very sticky, and 
then place them in the corners and rub them hard 
with a rounded brass rod or a fillet rubber. This 
presses out excess glue and gives them a round 
surface. 



O 



o 



Fig. 58. Fillet Rubber 



Tail The holes in the base must be cored. 

Prints An ordinary core print projecting from 

the base would not draw from the sand. 

To conquer this, run a tail from the print to the 




Fig. 59. Tail Prints 



In Wood Pattern Making 



81 



parting. This is called a tail print and must have 
a special box made for it. 



s< 


-\ ., 


<"l (\ 


\ !\ 


i! ii 




Fig. 60. Core Box for Tail Print 



CHAPTER X 

FACE PLATE WORK 

The Chuck The cylinder cover (Fig. 28) is 

or Face Plate a good example of face plate 
work. Find a three-inch face plate. 
Dress off one side of a board about 7" square and 
1" thick. Lay off a j" diameter circle on the board, 
and saw to this circle, on the band saw, if the 
shop is equipped with one. Screw the 3" iron 
face plate fast to the true side of this disc at its 
center. Face the disc off true on the lathe. Use 
a y% round point tool for roughing, and a 1" 
square point tool for finishing. Don't use a gouge 
on patterns turned on a face plate. Test the sur- 
face with a straight edge. Bore three Y^" holes 
into the wooden disc equal distances apart and 
about 2j4" from the center. This constitutes a 
chuck or face plate upon which we will turn a 
cylinder cover like Fig. 28. 

Cylinder Prepare a disc about 6y 2 " diameter 
Cover and 1" thick. Screw it fast to the 
chuck with ij4" No. 14 screws, in- 
serted in the three holes in the face plate. In 
screwing work to a face plate, be sure to select 
screws which do not go all the way through the 
job, and put them at such places that your tool 

82 



In Wood Pattern Making 83 

will not strike them when you turn deep portions 
of the job. 

Next turn down the edge to the proper diam- 
eter, using the spear point tool. Test with cali- 
pers. 



xzs: 



<s 




Fig. 61. Spear Point Tool 



The spear point is distinctly 
a pattern maker's tool, with 
which fine smooth work can 
be done, if the point is kept 
sharp, by frequent rubbing 
with a slip stone. The point 
should always be an acute 
angle and the tool must be fed 
very slowly. 



Fig. 62. Using the Spear Point 

Turn the depressions in the face, with the 
square point, leaving enough material on the sides 
to turn the fillets with a %" round point tool. This 
will be the cope side and the core forming these 
depressions, will hang in the cope. Give this 




8 4 



A High School Course 



side a coat of thin shellac and remove it from the 
face plate. 

Rechucking Turn a recess in the face plate 
about %" deep and of such a diam- 
eter that you can just force your newly turned job 
into it. Screw it fast with the newly turned face 
fitting against the chuck. The pattern can now 
be finished with little difficulty. 




Fig. 63. Section View Showing the Rechucked 
Cylinder Cover 

Segment Work 
Segments A circular pattern, if made of a 
solid piece, exposes considerable 
porous end grain, which dries out quickly and con- 



In Wood Pattern Making 85 

tracts, drawing the pattern into an oval shape. 
To overcome this, circular work is made of seg- 
ments which gives a continuous long grain 
around the piece. 

The segment in pattern making is most com- 
monly the sixth part of the rim of a circle, for it 
happens that a pair of dividers, set to the radius 
of a circle, will step around the circumference 
of the circle in six steps. The segment is, there- 
fore, made one-sixth of the circle, for convenience 
in laying out. 

Segments are laid down six to a course, one 




Fig- 63^2- Building Up a Segment Ring 

course forming a complete circle. They are- 
made of thin wood, so that it takes several 
courses, glued together, to build the job up to the 
required height. When the second course is 
glued to the first, the first segment of the second 
course is glued and nailed so that it laps over a 
joint in the first course. The second segment 
is fitted against the first and nailed and glued, 
and so on, until the course is completed, when 
the third course is begun, its joints falling directly 
over the joints in the first course. 

The segments are sawed out roughly on the 



86 



A High School Course 



band saw and must be smoothed and turned to 
the proper dimension on the lathe, after the job is 
built up ; therefore, the outside diameter must be 
made larger and the inside smaller than the re- 
quired finished pattern. The best way to get 
the proper sizes, is to prepare the pattern draw- 
ing and set your dividers by the drawing, al- 
lowing about Y^' for turning off. 

It is too laborious a task to lay all segments out 
with dividers; so procure a thin piece of wood 
about yg" thick and make a segment of it and use 
it to mark out the others by tracing around it. 
This is called a templet. 



Fi: 




Laying Out the Templet 



Piston Ring 

The piston ring is too slender a job for the 
machinist to turn out singly and, since piston 
rings are usually wanted in quantities, the pattern 
is made, so that several rings can be cut from the 
casting. 

If we turn out a hollow cylinder of the right 
diameter and 3" high the machinist can turn sev- 
eral rings from it. As was mentioned in Chapter 
III, the pattern maker endeavors to assist the 



In Wood Pattern Making 



87 



machinist in many ways. In this case, we can 
supply lugs or a flange, at the bottom of the ring, 
so that the machinist has no difficulty in fastening 













r**v 


* 


,-vi 


5510, 


h 1 

• 

*v 1 


♦ ' 


4 



Fig. 65. Piston Ring 



it to his face plate when he turns it. Without 
such provisions, he is likely to spring it out of 
shape. Taking these things into consideration, 
our pattern will look like Fig. 66. 

Prepare a wooden face plate or chuck, such as 
was used for the cylinder cover. While it is 
rotating on the lathe, hold a pencil against it, 
3%" from the center. This will trace a circle 7 ^2" 
in diameter, on the true face of the plate. Take 



88 



High School Course 



it to your bench and place it in the vise, face up. 
Rip strips J^" thick off the edge of 2" board, or a 
board of any thickness or width, and with a 
templet of 7J4" outside diameter and 4^" inside 




Fig. 66. Pattern for Piston Rings 

diameter, trace segments on the Y^' strips, after 
dressing off one side. One of two methods of 
laying out segments may be employed. (Fig. 67.) 




Fig. 6/. Two Methods of Economically Laying 



Out Segments 



Saw the segments right to the line, as neatly as 
possible. On the ends, a very small amount may 



In Wood Pattern Making 89 

be allowed for trimming. If many segments are 
needed, time can be saved by nailing several 
boards together. Two sizes of segments are re- 
quired, one for the flange and one for the body 
of the ring. 

Take a flange segment and trim off its ends, 
either on a trimmer or on a shoot board ; fit it 
to the pencil line on the face plate and nail it in 
place with i 1 /^' brads. Do not glue it fast, or it 
could not be removed when finished. 

Now trim off the end of another servient. If 
it forms a good joint with the first one and, at 
the same time, coincides with the pencil line, nail 
it in place. If not, then trim more off the end 
and try it again, etc. When the first course is 
completed start the second course (smaller seg- 
ments), lapping the joints as explained above. 
Nail and glue this course to the first. By this 
time, the course may have become uneven, owing 
to possible differences in thickness of segments, 
and it may be necessary to go to the lathe and 
true off the face of the course. Do this with as 
few cuts as possible and do it very carefully; as 
the glue is not dry and, if your tool catches, the 
segments will be ripped off. After facing off the 
segments, lay another course on and face it off, 
etc., until you have reached the proper height. 
When the glue is hard (usually it should set over 
night), turn the outside to the proper dimensions 
with the spear point tool, testing it with the out- 
side calipers. 



9o 



A High School Course 



Now swing the rest around, so that one arm 
will pass inside the pattern, and cautiously and 
slowly turn the inside smooth. The inside diam- 
eters must be tested with a pair of inside calipers. 




Fig. 68. Using the Inside Calipers 

After one coat of shellac is dry and sanded, 
take the job to the vise and with a chisel, carefully 
pry the job from the face plate. The nails that 
are protruding from the bottom, can be pulled out 
with carpenter's pincers. The heads can be 
drawn through the bottom course. Fill with 
putty the nail holes and any defects, caused by 
wood breaking out at the joints on the inside. 
Finish the shellacing. 



Lead Ladle 

A pattern for a lead ladle is a good example 
of segment work. In this case nearly every 
course is made of segments of different size. 



In Wood Pattern Making 



9* 




9 2 



A High School Course 



Prepare a face plate as before, larger than the 
diameter of the ladle, in order to have room for 
rechucking. The bottom of the bowl is made of 
a solid block about ^4" thick. We cannot put any 
nails into this job because it is so thin that we 
could not avoid striking them when turning. To 
fasten the bottom block to the face plate, plane 
one surface true, then spread a thin coat of glue 
upon it and upon the face plate. Spread a sheet 
of newspaper upon the face plate, place the glued 




Fig. 70. Arrangement of Segments for Lead Ladle 



side of the block on this and clamp. Let it stay 
in the clamp over night. Next morning, true off 
the block on the lathe and lay the segments 
which have been sawed of different sizes, as shown 
in Fig. 70. Make templets for the inside and out- 
side of the bowl similar to those made for the drip 



In Wood Pattern Making 93 

cup, and when the glue is dry, turn out the in- 
side of the cup to fit the templet, using a round- 
nosed tool. Turn as much of the outside as can 
be conveniently reached. Set the calipers to the 
thickness of the bowl and test this portion. Give 
it one coat of shellac and sand paper. Now with 
a chisel, pry under the bottom block and the 
pattern will readily split off, half of the paper 
sticking to each piece. Now rechuck the pattern, 
turn the outside to fit its templet, and remove it 
from the lathe. 

To make the handle, take a block of wood 
large enough for the purpose and gouge one end 
concave, until it fits the outside of the cup snugly ; 
then carve the handle from this block. The 
spout is fitted in the same manner. The spout 
must be set in about 1/16", to avoid a feather edge 
when shaping it. Glue the whole block in and 
carve the spout out, after the glue is dry. 

It would be a good plan to set the handle in, 
though it is much easier to run small screws 
(No. 5) through the cup into the handle. 

In fitting blocks to a convex surface, chalk the 
surface, then rub the partly gouged block over 
the chalk. All lumps will be marked and may 
be cut down. Repeat this operation until there 
is a perfect bearing. 

Locomotive Bell 

Some students might prefer to make a locomo- 
tive bell instead of the lead ladle. The experience 



94 



A High School Course 



gained is about the same but the bell is more at- 
tractive. Study the directions for making the 
lead ladle carefully, and apply them to the bell. 
The paper method of fastening the pattern to the 




£e//Afef*/ 



face plate is probably not safe for the bell. Make 
the bottom block thick enough so that you can 
fasten it with screws. Use your layout to find 
the length of screw necessary. Don't have them 
so long that you will strike them, when turning 
the inside. 



In Wood Pattern Making 95 

The spindle on top of the bell, should be turned 
between centers and provided with a pin, which 
should fit in a hole turned in the bell. 

For detailed information on making a pattern 
for a 12^" diameter bell consult the I. C. S. Refer- 
ence Book on Pattern Making. 




a 

WHEELS 

Hand Turn the pattern for the hand wheel 

Wheel from a plain board. Turn a solid web 
between the hub and the rim. Use a 
templet to get the rim circular. Rechuck it, to 
turn both sides alike. After you have finished 
turning, lay out the arms with clean cut lines. 
Bore a half inch hole in the spaces between the 
arms, insert a coping saw, and saw to the lines. 
Shape the arms with a pocket knife and sand 
paper them. 

Wheels are not usually parted. The moulder 
cuts the parting and the impression of the upper 
half is lifted off in the cope. 

Gear Blank 

Arms In order to avoid the weak cross grain 
in the arms of a straight arm wheel, the 
set of arms or spider, as it is frequently called, is 
made of three pieces of wood joined together at 
the center. 

To make a set of arms for this wheel, dress up 
three pieces J4" X i%" X ioj4". Gage center lines 
upon them, lay two of them out like drawing 
(Fig. 74), and cut out the gains thus outlined. 
96 



In Wood Pattern Making 



97 




\'3 

Fig. f2. Hand Wheel 



A High School Course 




A7feert 



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Fig. 73. Gear Blank 



In Wood Pattern Making 



99 




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i 






/or- 



Fig. 74 




Fig- 75 

Fit the pieces together. Do not force them or 
they will spring out of shape. 

Lay out the pair, as shown in Fig. 75, and cut 
out the gain thus outlined. Slip the third piece 
into the gain and make knife lines, where it 



IOO 



A High School Course 



emerges. Complete the lay out of this piece and 
cut out the material within the lines as shown in 
Fig j6. Fit the three together without forcing 
and glue them. 



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Fig. 76 

The drawing for the wheel shows the arms 
tapered from %" thick at the hub, to y 2 " thick at 
the rim. Perform that operation. Lay out the 
arms and saw to the lines. (Fig. jj.) 




Fig. 77. Arms 



In Wood Pattern Making ioj 



Gear In these days of improved machinery, 

Wheel the pattern maker is seldom called upon 
to build a gear wheel. Instead, for small 
wheels, a gear blank is made and the teeth cut 
out of the metal by gear cutting machines. To 
build a blank for the wheel shown in this exercise, 
allow for finish on the outside or addendum 
circle, and build the heavy rim including the web, 




Fig. 78 

of segments. Be careful not to run the lathe 
at too high a speed. Saw out spaces in the web in 
which to fit the ends of the arms. (Fig. 78.) 
Glue the arms in place. Run a dowel pin, or nails, 



102 A High School Course 

through the rim, into the ends of the arms. Shape 
the arms to the elliptical cross section, as shown 
at S. Fig. 73, with a pocket knife, small spoke 
shave, and sand paper. 

Turn up the bosses for the hub separately, and 
nail and glue them in place. The hole in the hub 
should be cored. Place a print on one side only. 
This being a very short core, there is no neces- 
sity for having a cope print. A short core is not 
likely to be moved out of its vertical position. 
Draw a black circle on the cope side, to indicate 
to the moulder that the core comes all the way 
through. No core box need be made for this. 
Every foundry has standard core boxes or a core 
machine. The moulder takes a standard i 1 /\.' r core 
and cuts it off to the correct length for use in 
this wheel. 



In Wood Pattern Making 



103 




CHAPTER XII 

STAVES AND STRIPS 

Flange In order to prevent the distortion 
Pipe caused by the shrinkage of wood across 
its grain and to save material, a cylinder 
over ten or twelve inches in diameter is staved. 
(Fig. 22.) 

To determine the size and shape of the staves 
make a layout of the cross section of the pipe 
(Fig. 80). Decide how thick the staves should 




Fig. 80. Layout to Determine the Shape of the 
Staves 

be, to produce the proper strength. In this case, 
they should be made of 1" lumber. Allowing }£" 
for dressing and turning and about 1/16" for the 
flattening of the curve at "F" (Fig. 80), we may 
draw a circle "C," 13/16" inside of the circle "B" 
which represents the outside of the pipe. Judge 

104 



In Wood Pattern Making 105 

the number of staves you should use (in this ease, 
16), and divide the semi-circle "C" into eight 
equal parts. Connect the division points by 
straight lines. This represents the bottom of 
the stave. To represent the top, draw a line par- 
allel to it and 15/16" from it. The edges are rep- 
resented by lines drawn from the center through 
the division points. Set the bevel to angle "A" 
(Fig. 80). Saw sixteen strips from a 1" board, 
a little wider than necessary, and 15J/6" long; 
dress them off to the correct thickness, and plane 
the edges to the correct angle. This can be tested 
with the bevel. 

This work is very simple, if the shop is 
equipped with a jointer, planer, and circular saw; 
but it can also be done with a band saw and hand 
plane. To get the angle on the edges, set the 
circular saw, or band saw table, to the proper 
angle, as given by the bevel. 

Next get four half heads, about 9^" in diam- 
eter, and 1" thick. Lay out circle 'C" (Fig. 80), 
divide it into 8 parts, and flatten the curve to re- 
ceive the 8 staves. (H Fig. 80.) Draw two par- 
allel lines perpendicular to the edge of some 
straight board, and 15 1/16" apart. Toe-nail a 
half head to coincide with each line. Nail a 
brace in place against each head, to keep it per- 
pendicular to the board, and proceed to nail and 
glue the staves in place. (Fig. 81.) 



io6 



A High School Course 



//eac/j 




Fig. 81 

This is one-half of the pattern. Proceed with 
the other half in the same way, and then pin the 
two halves together with dowel pins. To mark 
the centers for the dowel pin holes so that they 
will match in both halves, place two small brads 
on the joint between the halves, and pound the 
halves together with a stroke of a mallet. The 
head of the brad will mark both halves at the 
same point and, if this is used as a center for 
the auger bit, the holes can be bored to match, 
The pins should be placed in the heads. 

The ordinary spur and cone center will not do 
for turning a job of this size. Iron plates 
(Fig. 82) are made, which can be screwed fast to 
the job. 



c:: 



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OO00 

—e— 

00 00 



Fig. 82 



In Wood Pattern Making 



107 



Each contains conical depression into which a 
cone center fits and cone centers are used in the 
head and tail stock. The job is revolved by a 
dog, projecting from one of the plates and passing 
into a slot in a face plate. If no such center plates 
are at hand, the spur center can be made to do 
the work by making a pair of hardwood blocks, 
about 4" square provided with screw holes and 
deep cuts to receive the spur and cone centers. 
(Fig. 83.) Pinch dogs should be driven into the 
end across the joint, to help hold the job together. 



tfar</tt/oo(/ 




fiircfifloj. 



Fig. 83. Center Plate 



To turn this job, use the square nosed tool 
and run the lathe at its slowest speed. If you 
forget this warning, you may have a bad wreck 
and probable injury; as great speed will throw 
the job out of the lathe. Do not attempt to 
caliper the job while it is in motion. Use a 
straight edge to test it lengthwise. 



io8 



A High School Course 



Turn recesses on the ends to receive the flange 
(Fig. 84). Make the flange of four segments, nail 
and glue them to the cylinder, and turn it to size. 
If your lathe will not swing twelve inches, cut 
down the flange to a smaller diameter. 





Corejori'fft 




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« 






T 


1 


- 


— 


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Fig. 84 

The core prints can be sawed out of two-inch 
stuff, dressed off with a spoke shave, and nailed 
and glued in place ; or they may be turned on a 
face plate. 

The core box should be stripped up. Make 
heads, as shown in Fig. 85, and nail and glue 



X^ 


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^ 


\ ^** \ 




\ ' 


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X 




X 


• 


% 



Fig. 85 



In Wood Pattern Making 



109 



y% strips inside. The narrower the strip the 
less to dress out. This box can be dressed out 
with a spoke shave, or round bottom plane of 
suitable radius. The core prints can be fastened 
on the end, and boards, nailed across the ends of 
the core print. (Fig. 86.) 

This half box is all that is necessary for such a 
job. The core maker rams the box up twice and 
pastes the two half cores together, to form a 
whole. This can be done with any symmetrical 
core. 



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\ "VW 


\ 


V, 





Fig. 86. Core Box 



Loose Pieces 

Cylinder The cylinder cover, given in Fig. 87, 
Cover would be impossible to mould by any 
method so far considered, without a 
troublesome core box. By resorting to loose 
pieces, the operation is simplified. 

This pattern should be parted on the line "A-B." 
Both halves can be turned on a face plate. The 
round part "P" should be turned straight, and 



no 



A High School Course 




Fig. 8?. Cylinder Cover 



In Wood Pattern Making 



in 



the ears "E, E," set in, as shown in Fig. 88, but 
not permanently fastened. 




Fig. 88. Loose Pieces 



They are held in place by loose dowel pins, or 
large nails, slipped into holes bored through the 
ear into the pattern. 

The moulder rams up, until the loose pieces 
are covered with sand, when he digs into the sand 
and removes the pins. The loose pieces will then 
be held in place by the sand. When the ramming 
up is completed and the pattern drawn, the pieces 
remain in the sand. The moulder reaches down, 
and with a sharp point picks them out. 

Pupils finishing this course before the end of 



112 A High School Course 

the year are prepared to build a set of patterns 
for a simple machine which could be designed 
in the drawing room. The foundry, forge and 
machine shops should co-operate in building the 
complete machine. Patterns for such machines 
may be substituted for the given exercises if they 
cover the same points. 



INDEX 



Arms, for wheel.... 96 

Assembling- shop.... 4 

Back saw 14 

Battens 41 

Bevel 16 

Bit, auger, how to tell 

size 56 

Bit, sharpening 12 

Cone print 66 

Calipers, inside 90 

Calipers, outside .... 60 

Castings 3 

Center plate 106 

Cheek 23 

Chisel 16 

Chisel, square point. . . 64 

Chisel, turning ...... 59 

Cope 23 

Core 25 

Core box 26 

Core box, standard.. 102 

Core prints 27 

Core sand 26 

Cores, balanced 27 

Cores, dry sand 27 

Cores, green sand ... 27 

Cores, horizontal .... 27 

Cores, vertical 27 

Cupola 3 

Designer, machine.... 2 

Draft 32, 47 

Draftsman, machine.. 2 

Drag 23 

Drawing, mechanical, 

shop 2, 44, 46 

"Drawing Cut" .... 15, 16 

Drawing, in moulding 25 
Drawing, pattern 

maker's 47 

Draw screw 25 

Kiln, dry 40 

"f" 46,48 



Face edge 17 

Face plate, wood.... 82 

Face side 17 

Fillets 78 

Fill up pieces 42 

Finish, an allowance 

on patterns 45 

Finish, in machine 

shop 3 

Flask 22 

Forge shop 4 

Foundry 2 

Foundryman 3 

Gases, in a mould.... 25 

Gage 13 

Gate 25 

Gouge, roughing .... 58 

Holes, under %" 56 

Instruction card 17 

Knowledge a pattern 
maker must pos- 
sess 78 

Loose pieces in 

Lumber 39 

Machine shop 3 

Manufacturing plant. . 4 

Mould 2,20 

Mould board 23 

Moulder 2 

Moulding sand 22 

Moulds, loam 20 

Moulds, dry sand.... 21 

Moulds, green sand.. 21 

Open joints 4 

Parting, moulder 

cuts a 34 

Pattern making, 

definition of ... . 39 

Pattern 2, 23 

Patterns, parted .... 33 

Pinch dogs 107 

Plane, blocks 15 



Plane, fore, jack and 

smoothing 10 

Pouring 25 

Print, cone 27 

Rammer 23 

Rapping 25 

Re-chucking 84 

Rule, shrinkage 32 

Scribe 14 

Seasoning lumber.... 40 

Segments 84 

Sharpening lathe 

tools 61 

Sharpening paring 

tools 12 

Shellac 52 

Shellac, applying it 

to turned work. . 68 
Shrinkage of metals.. 31 
Shrinkage, an allow- 
ance in patterns. . 47 



Shrinkage rule 32 

Slicker 24 

Spear point tool 83 

Sprue . 25 

Sprue pin 23 

Staves 104 

Swab 25 

Tail prints 80 

Templets 75 

Trowel 24 

Try square 13 

Tumbling barrel 3 

Vents 25 

Vent wire 25 

Wheels 96 

Wood turning 57 

Wood working exer- 
cise 17 

Working to a line... 14 

Wrought iron 4 



